Measurement of biodynamic response of human hand–arm system

Biodynamics of the human hand–arm system is one of the most important foundations for understanding hand-transmitted vibration exposure and its health effects. Considerable differences among the reported data of the biodynamic response (BR) of the hand–arm system have been observed. A significant portion of the differences are believed to have resulted from instrumentation problems and/or computational algorithm errors. To help establish a reliable and accurate methodology for BR measurement, this study addresses the fundamental instrumentation issues. Specifically, the general theory of the driving-point BR is reviewed and summarized. An accurate mass cancellation method for BR measurement is identified and further developed. A set of methods is proposed to systematically examine and calibrate the BR measurement system. Based on the experimental results and theoretical analyses, several instrumentation and algorithm problems are identified. This study demonstrated that the instrumentation problems can be resolved or avoided by appropriately selecting the force and motion sensors, improving the structure design of the instrumented handle and fixture, using the frequency-domain method for the handle mass cancellation, and conducting the static and dynamic calibrations of the measurement system using the proposed methods. The information and knowledge presented in this paper can help to generate reliable experimental data in further BR studies.